The present invention relates to a surgical retractor assembly and more particularly to a retractor assembly useful in surgery involving bones or hard tissue structures, such as in spine or joint surgery.
In many surgical operations it is customary to employ a retraction apparatus in which a frame or mounting ring rests over the patient surrounding the surgical opening, and a number of retractors may be movably attached to the frame and flexibly positioned, with various clamping or positioning mechanisms, to reach into the surgical opening and retract surrounding or obstructing tissue or organs, or to stabilize or position tissue or organs that are being worked on. In general, such retractors may include a blade or spoon-like member, or various gripping members, that each extend from an elongated handle or stem, and the stem moves within a clamping mechanism that mounts on the mounting ring and locks the blade or gripping member in a selected position. The clamping mechanism may itself have a mechanical structure allowing one or more additional degrees of movement in rotation or displacement, so that both the position and orientation of the blade may be quickly set and locked. Various common machine elements such as swivel ball mounts, arcuate rack or tilt mounts, ratchet or rack adjustment and locking mechanisms, or screw clamps may be incorporated in the clamping structures to provide assemblies that are moved by hand into the desired position and locked.
By way of example, one commercially useful system is shown in the various patents of John R. Bookwalter, et al. such as U.S. Pat. Nos. 4,424,724; 4,254,763; 4,421,108; 5,375,481; and 5,520,608. This system is made and marketed by Codman. In the Bookwalter system, the frame element is a flat ring with regular notches. The ring is held by a post that clamps to the side rail of the operating table, so the ring is suspended in a plane above the surgical site. The plane of the ring sets one constraint on the movement of the retractor units, and allows the various retractor clamp assemblies to move into position and lock with a sliding movement that is conveniently set with one hand.
Many other surgical equipment suppliers also make surgical retractor systems, which may, for example be distinguished by one or more novel blades, clamps or frames, by a dimension or shape adapting the system to a particular surgery, or by features such as a round clamping ring or linked ring segments, to achieve their positioning and retracting abilities.
In general, such systems are intended to efficiently perform their function of retracting or positioning tissue in the surgical arena in a manner that allows simple adjustment with few motions by the surgeon during the course of a procedure, and without interfering with or obstructing the access lines necessary for manipulation within the surgical arena. In effect, a surgical retractor system requires a high degree of versatility to reach to and to retract or reposition, various tissues or organs as the surgical procedure proceeds. To a large extent, when it is simply a question of retracting soft tissue structures during abdominal or thoracic surgery, the required tasks can be performed with a set of just a few contoured blades having various lengths that extend proximate to the surgical opening as shown in the aforesaid patents. However, when the tissue does not consist of soft organs or structures spaced about a large opening but instead requires retraction of muscle or connective tissue from bony structures, the alignment of the blade with the tissue becomes more difficult, and it may be awkward to correctly insert or align the available clamping structures and retraction blades with the intended tissue. This is especially true for operations in and around bones and joints.
Accordingly, it would be desirable to develop an improved surgical retractor blade. It would also be desirable to develop a surgical retractor system useful for surgery on bones and joints.
It would also be desirable to develop a surgical retractor system useful for spinal surgery.
It would further be desirable to develop such a retractor blade which is also usable with existing clamps and rings.